Hurricane Katrina churned through Florida's densely populated southeastern coast Thursday with sustained winds of 80 mph and lashing rain. Two people were killed by falling trees.

The storm strengthened into a Category 1 hurricane just before it made landfall along the Miami-Dade and Broward county line between Hallandale Beach and North Miami Beach. Weather officials said flooding was the main concern as the storm dropped 10 inches of rain in Key Biscayne.

Rain fell in horizontal sheets, seas were estimated at 15 feet and wind gusted to 92 mph, toppling trees and street signs. Florida Power & Light said more than a million customers were without electricity.

An overpass under construction in Miami-Dade County collapsed onto a highway, authorities said. No injuries were immediately reported.

Late Thursday, Katrina was centered in northwest Miami-Dade County, heading west at 6 mph. An estimated 5.9 million Florida residents were in the storm's projected path.

The storm proved fatal for two people who ignored warnings to stay inside until the worst was over. A man in his 20s in Fort Lauderdale was crushed by a falling tree as he sat alone in his car, while a pedestrian was killed by a falling tree in the Fort Lauderdale suburb of Plantation.

Source: Agencies